Jason A. Kautz’s research while affiliated with University of Northern Iowa and other places

For Abstract see ChemInform Abstract in Full Text.

Treatment of 7-NH(2)Bu(t)-nido-7-CB(10)H(12) in tetrahydrofuran (THF) with LiBu(n)(3 equiv) and then [ReBr(CO)(3)(THF)(2)] gives the rhenacarborane dianion [1-NHBu(t)-2,2,2-(CO)(3)-closo-2,1-ReCB(10)H(10)](2-), isolated as the bis-[N(PPh(3))(2)](+) salt (4). Iodine oxidation of this Re(I) intermediate gives the Re(III) complex [1,2-mu-NHBu(t)-2,2,2-(CO)(3)-closo-2,1-ReCB(10)H(10)] 6 in which the carborane functions formally as an 8-electron (6pi+ 2sigma) donor. Reaction of with ligands L in the presence of Me(3)NO gives substituted products [1,2-mu-NHBu(t)-2,2-(CO)(2)-2-L-closo-2,1-ReCB(10)H(10)][L = PPh(3)(7a), CNXyl (7b; Xyl = C(6)H(3)Me(2)-2,6), or Bu(t)C triple bond CH (7c)]. Formation of complex 7c is unexpectedly accompanied by [1,2-mu-NHBu(t)-2,2-(CO)(2)-3,2-sigma:eta(2)-{C(=CHBu(t))-CH=CHBu(t)}-closo-2,1-ReCB(10)H(9)] 8a, in which an alkyne-derived dienyl group is bound to both the rhenium centre and to an adjacent boron vertex. Complex 8a is also obtained from 7c with Bu(t)C triple bond CH and Me(3)NO. The same reaction of 7c, using PhC triple bond CH or CNXyl instead of Bu(t)C triple bond CH, gives, respectively, [1,2-micro-NHBu(t)-2,2-(CO)(2)-3,2-sigma:eta(2)-{C(=CHBu(t))-CH=CHPh}-closo-2,1-ReCB(10)H(9)] 8b and [1,2-micro-NHBu(t)-2-Bu(t)C triple bond CH-2-CO-2-CNXyl-closo-2,1-ReCB(10)H(10)] 9. Addition of donors L to results in displacement from rhenium of the pendant dienyl moiety, yielding [1,2-mu-NHBu(t)-2,2-(CO)(2)-2-L-3-{C(=CHBu(t))-CH=CHBu(t)}-closo-2,1-ReCB(10)H(9)][L = PMe(3)(10a), CNBu(t)(10b)]. Single-crystal X-ray diffraction analyses have confirmed the novel structural features of compounds 6, 7c, 8b and 9.

Treatment of the 11-vertex carborane anion [closo-2-CB(10)H(11)](-) with Ni(0) reagents in tetrahydrofuran (THF) affords-via oxidative insertion reactions-12-vertex Ni(II) complexes, isolated as the salts [N(PPh(3))(2)][2,2-L(2)-closo-2,1-NiCB(10)H(11)] (L = CO (1a), CNBu(t) (1b), and CNXyl (1c; Xyl = C(6)H(3)Me(2)-2,6); L(2) = cod (1d; cod = 1,2:5,6-eta-cyclo-octa-1,5-diene)). One CO ligand in 1a is readily replaced by donors L' in the presence of Me(3)NO to give the species [N(PPh(3))(2)][2-CO-2-L'-closo-2,1-NiCB(10)H(11)] (L' = PEt(3) (1e), PPh(3) (1f), CNBu(t) (1g), and CNXyl (1h)). The anionic complexes themselves readily react with hydride abstracting reagents in the presence of donor ligands to yield zwitterionic complexes in which boron vertexes bear substituents that are bound through C, N, or O atoms. Thus, for example, 1c with H(+) and CNXyl gives [2,2,7-(CNXyl)(3)-closo-2,1-NiCB(10)H(10)] (2b), while 1f with Me(+) in the presence of OEt(2) affords [2-CO-2,11-{mu-PPh(2)(C(6)H(4)-o)}-7-OEt(2)-closo-2,1-NiCB(10)H(9)] (4), in which an additional cycloboronation of one phosphine phenyl ring has occurred. In contrast, 1f with Me(+) in the presence of NCMe gives a mixture of the isomers [2-CO-2-PPh(3)-7-{(X)-N(Me)=C(H)Me}-closo-2,1-NiCB(10)H(10)] (X identical with E (5c) and Z (5d)). X-ray diffraction analyses of compounds 1a, 2b, 4, and 5c confirmed their important structural features.

We have synthesized and characterized a series of alkyl and aryl‐(4‐methyl‐6‐nitro‐quinolin‐2‐yl)amines through a high‐yield, three‐step procedure starting from 4‐methylquinolin‐2‐ol. Nitration using concentrated nitric/sulfuric acids, followed by chlorination in phosphorus oxychloride, yielded 2‐chloro‐4‐methyl‐6‐nitro‐quinoline. All of the intermediates and aminated products have been characterized by multinuclear (H and C) NMR spectroscopy, elemental analysis, and, in the case of the two title compounds (ethyl and cyclohexyl‐(4‐methyl‐6‐nitro‐quinolin‐2‐yl)amine), a single crystal X‐ray structure was obtained to verify the nature of the new materials.

The manganacarborane dianion in [N(PPh(3))(2)][NEt(4)][1,1,1-(CO)(3)-2-Ph-closo-1,2-MnCB(9)H(9)] (1b) reacts with cationic transition metal-ligand fragments to give products in which the electrophilic metal groups (M') are exo-polyhedrally attached to the {closo-1,2-MnCB(9)} cage system via three-center two-electron B-H --> M' linkages and generally also by Mn-M' bonds. With {Cu(PPh(3))}(+), the Cu-Mn-Cu trimetallic species [1,6-{Cu(PPh(3))}-1,7-{Cu(PPh(3))}-6,7-(mu-H)(2)-1,1,1-(CO)(3)-2-Ph-closo-1,2-MnCB(9)H(7)] (3a) is formed, whereas reactions with {M'(dppe)}(2+) (M' = Ni, Pd; dppe = Ph(2)PCH(2)CH(2)PPh(2)) give [1,3-{Ni(dppe)}-3-(mu-H)-1,1,1-(CO)(3)-2-Ph-closo-1,2-MnCB(9)H(8)] (5a) and [1,3,6-{Pd(dppe)}-3,6-(mu-H)(2)-1,1,1-(CO)(3)-2-Ph-closo-1,2-MnCB(9)H(7)] (5b), both of which contain M'-Mn bonds. The latter reaction with M' = Pt affords [3,6-{Pt(dppe)}-3,6-(mu-H)(2)-1,1,1-(CO)(3)-2-Ph-closo-1,2-MnCB(9)H(7)] (6), which lacks a Pt-Mn connectivity. Compound 6 itself spontaneously converts to [1-Ph-2,2,2-(CO)(3)-8,8-(dppe)-hypercloso-8,2,1-PtMnCB(9)H(9)] (7b) and thence to [3,6,7-{Mn(CO)(3)}-3,7-(mu-H)(2)-1-Ph-6,6-(dppe)-closo-6,1-PtCB(8)H(6)] (8). This sequence occurs via initial insertion of the {Pt(dppe)} unit and then extrusion of {Mn(CO)(3)} and one {BH} vertex. In the presence of alcohols ROH, compound 6 is transformed to the 7-OR substituted analogues of 7b. X-ray diffraction studies were essential in elucidating the structures encountered in compounds 5-8 and hence in understanding their behavior.

The crystal structure of the complex [Nd(NO3)(OPPh3)] (1) was obtained by single-crystal X-ray diffraction. The central neodymium(III) ion is nine coordinate arranged in a tricapped trigonal prism geometry. Crystallization of 1 occurs in the centrosymmetric monoclinic space group P21/c (No. 14) with a = 14.6496(9), b = 18.4506(11), c = 20.5491(11); ß = 102.925(3)°; and Z = 4.

The four title compounds have been synthesized and characterized by 1H, 13C and 31P NMR spectroscopy and their identities confirmed by elemental analysis and X-ray crystallography. But2P(E)NHPrn [E=Se (1); E=Te (2)] and Ph2P(E)NHPrn [E=Se (3)] were prepared by the metathesis reaction of LiNHPrn with the appropriate chlorophosphine in diethylether at −78 °C, followed by reaction with elemental selenium or tellurium at reflux temperatures. (1) and (2) are isostructural with PSe 2.1163(14) Å and PTe 2.3642(13) Å. In (3) a PSe bond length of 2.1159(10) Å is observed. (4) was prepared by the additional of two equivalents of diethylchlorophosphine to the dilithium salt of n-propylamine.

Treatment of Na2[7,8-R2-nido-7,8-C2B9H9] (R = H, Me) with the reagent [Mn(NCMe)3(CO)3][PF6] affords the anions [3,3,3-(CO)3-1,2-R2-closo-3,1,2-MnC2B9H9]-, typically isolated as Cs+ or [N(PPh3)2]+ salts. These anions interact with cationic metal fragments {M(PPh3)}+ (M = Cu, Ag, Au) to give the bimetallic compounds [3,8-{M(PPh3)}-8-μ-H-3,3,3-(CO)3-1,2-R2-closo-3,1,2-MnC2B9H8], for which the structures of the Cu and Au species (R = H) have been confirmed by X-ray diffraction studies. In contrast, other electrophiles such as H+ and Me+ abstract hydride from carborane boron vertexes, which in the presence of donors (L) produces the neutral zwitterions [8-L-3,3,3-(CO)3-1,2-R2-closo-3,1,2-MnC2B9H8]. The halogenated derivatives [8-X-3,3,3-(CO)3-1,2-R2-closo-3,1,2-MnC2B9H8]- (X = Cl, Br, I) of the parent anions are obtained by hydride abstraction in halogenated solvents or by direct reaction with Br2 or I2. Moreover, further cluster functionalization is achieved by treating the 8-iodo species with the Grignard reagents R‘MgBr, leading to the anions [8-R‘-3,3,3-(CO)3-1,2-R2-closo-3,1,2-MnC2B9H8]-. When the substitution processes are repeated, the latter series of anions yield compounds with yet more functionality. Crystallographic studies of the boron-substituted derivatives [8-{(E)-N(Me)C(H)Me}-3,3,3-(CO)3-closo-3,1,2-MnC2B9H10], [N(PPh3)2][8-(p-C6H4Me)-3,3,3-(CO)3-1,2-Me2-closo-3,1,2-MnC2B9H8], and [4-{(Z)-N(Me)C(H)Me}-3,3,3-(CO)3-1,2,8-Me3-closo-3,1,2-MnC2B9H7] confirmed their structures and the sites of cage substitution.

In the neodymium(III) complex, [Nd(NCS)3{OP(C6H5)3}4], the coordination about the central neodymium(III) ion is sevenfold with a slightly distorted capped trigonal prismatic arrangement.

The crystal structure of the title copper(II) complex, [Cu(NCS)2(C5H5N)4], shows a tetragonally distorted octahedral coordination about the central copper(II) ion. The Cu ion lies at a site with symmetry.